The present invention is related to an improved shift handle of a bicycle, and more particularly to an improved cord-pulling and releasing structure of the shift handle of the bicycle. By means of the easy cord-passing structure, the cord-passing operation becomes very easy, convenient and time-saving.
U.S. Pat. No. 5,476,019 discloses a shift handle of bicycle ( as shown in FIGS. 1 and 2 thereof ). One end of the steel cord 66 for driving a chain-shifting mechanism is conducted into the casing 16 of the shift handle and wound and fixed on outer circumference 72 of a rotary member 60. By means of rotating the rotary member 60, the steel cord 66 is wound or unwound for driving the chain-shifting mechanism and changing the sprocket.
According to the above arrangement, when assembling the shift handle, the steel cord 66 must be first conducted into the outer circumference 72 of the rotary member 60 and then conducted into the conduit 30 of the casing 16. Then, the steel cord 66 is conducted out of the other end of the conduit 30. Then, the steel cord 66 is conducted into a flexible tube 36 with the first end 76 of the steel cord 66 fixed on the rotary member 60. The steel cord 66 has a certain resilience so that it can be hardly snugly wound on the rotary member 60. It is necessary for an operator to pull and tension the steel cord 66 with one hand and install the locating catapult 44 into the arched catapult locating slot 42 of the casing 16 with the other hand. Then, the shift handle 18 is aimed at the assembling face of the casing 16 and mounted therein. The sealing cover 84 is then locked and the second end of the steel cord is fixed at the chain-shifting mechanism. During the entire assembling procedure, the steel cord 66 will always bound away to obstruct the assembling operation. Therefore, it is laborious and time-consuming to assemble the shift handle. This greatly affects the production efficiency.
It is therefore a primary object of the present invention to provide an easy cord-passing structure of shift handle of a bicycle, in which the cord-guiding link is connected between the steel cord inlet and outlet of the fixing casing, whereby the steel cord can be nearly linearly passed from the steel cord inlet through the cord-guiding passage to the steel cord outlet and out of the fixing casing. Therefore, it is unnecessary to wind the steel cord around the outer circumference of the rotary member and the cord-passing operation becomes very easy, convenient and time-saving.
It is a further object of the present invention to provide the above easy cord-passing structure in which the cord-guiding link has a straight cord-guiding passage for the steel cord to pass therethrough. One end of the cord-guiding link has a cord head locating hole in which the cord head of the steel cord is engaged. After the steel cord is passed through the cord-guiding passage, the steel cord is firmly fixed in the cord-guiding link. Accordingly, the steel cord and the cord-guiding link are prevented from freely bounding to interfere with the cord-passing operation and the cord-passing operation is facilitated.
It is a further object of the present invention to provide the above easy cord-passing structure in which the cord-guiding link not only permits the steel cord to pass therethrough, but also is able to pull the steel cord. In addition, the cord-guiding link has a hook section providing locating effect. The cord-guiding link has both functions of cord-pulling of the conventional rotary member and location of the conventional locating catapult. Therefore, the cord-passing structure of the present invention is simplified and the assembly is facilitated.
According to the above objects, the Easy cord-passing structure of shift handle of a bicycle of the present invention includes: a fixing casing formed with a central through hole for the handle of the bicycle to pass therethrough, the fixing casing being fixed around the bicycle handle and having: an annular inner cavity formed around the through hole, a locating rack having multiple waved locating teeth, the locating rack having a first end and a second end, the locating rack integrally extending from the annular inner cavity with the second end suspending in the inner cavity, a steel cord inlet being formed through the fixing casing and adjacent to the second end of the locating rack, a steel cord outlet being also formed through the fixing casing and adjacent to the first end of the locating rack; a rotary member rotatably disposed on the bicycle handle and connected with the shift handle, the rotary member being positioned in the annular inner cavity of the fixing casing and rotatable along with the shift handle; and a cord-guiding link having a first end and a second end, the first end being pivotally connected with the rotary member, the second end having a hook section snugly latched with one of the locating teeth, the hook section being slidable into the tooth trough of any other locating tooth and latch therewith, the cord-guiding link having a cord-guiding passage passing from the first end to the second end of the cord-guiding link, the cord-guiding passage being positioned between the steel cord inlet and the steel cord outlet, whereby the steel cord can be conducted from the inlet through the cord-guiding passage to the outlet and out of the fixing casing.
The easy cord-passing structure of shift handle of a bicycle further includes a retardant driving mechanism which includes a slide slot and a pivot section slidably disposed in the slide slot, one of the slide slot and the pivot section being disposed at the first end of the cord-guiding link, while the other being disposed on the rotary member, whereby the shift of the cord-guiding link is retarded after the rotation of the rotary member.
The easy cord-passing structure of shift handle of a bicycle further includes a cam fixed on the rotary member and rotatable along with the rotary member, the cam pushing the cord-guiding link and making the same pivotally rotate about the first end thereof, whereby the hook section of the cord-guiding link is disengaged from the locating tooth.
In the easy cord-passing structure of shift handle of a bicycle, the first end of the cord-guiding link further has a cord head locating hole in which the cord head of the steel cord is engaged.
The easy cord-passing structure of shift handle of a bicycle further includes a cord-guiding tube disposed in the annular inner cavity of the fixing casing, one end of the cord-guiding tube being connected at the steel cord outlet of the fixing casing, while the other end thereof being formed with a trumpet opening and adjacent to the first end of the locating rack, whereby when the rotary member is turned to a maximum cord-loosening position, the first end of the cord-guiding link is right aimed at the steel cord inlet of the fixing casing, while the second end of the cord-guiding link is right aimed at the trumpet opening of the cord-guiding tube and the steel cord inlet, the cord-guiding passage, the cord-guiding tube and the steel cord outlet are connected to form a continuous straight passage, the steel cord being smoothly conducted from the steel cord inlet into the fixing casing and through the cord-guiding passage and the cord-guiding tube and conducted out of the fixing casing from the steel cord outlet.
The present invention can be best understood through the following description and accompanying drawings wherein: